With Sayako and Toune trapped in the castle of Lucky Thoroughbred, Bocca and Koko sneak in to save both. While on the way in, the two get more than a bit comfortable with each other, and Coco tells her story to the boy. Within the castle, a helpless Sayako is reminded of her old family, and of her brother's "achievement" to become a Monster Union agent. Meanwhile, the two Melos Warriors go separate ways. Bocca eventually meets up with Lucky Thoroughbred, agreeing to a race with his robot monster over a lake of water, since if Bocca wins, his friends would be released. At the same time, Koko in off saving Toune, when met up with Flying Bunny, where trouble starts to occur. What happen there? And can Bocca win the race with his flightless Aibar-Machine?

　　牧歌和可可以及阿光他们会面了，可是小夜子却被拉奇．撒拉布雷多抓走。代理人拉奇．撒拉布雷多的真正身份其实就是小夜子的哥哥秀马。自称为「被生为这个世界上最特别的男人，就是这个如此幸运的我」的秀马，从小就被父母宠爱于一身，曾经，他甚至打算牺牲掉小夜子成就自己……。

牧歌和可可以及阿光他們會面了，可是小夜子卻被拉奇．撒拉布雷多抓走。代理人拉奇．撒拉布雷多的真正身份其實就是小夜子的哥哥秀馬。自稱為「被生為這個世界上最特別的男人，就是這個如此幸運的我」的秀馬，從小就被父母寵愛於一身，曾經，他甚至打算犧牲掉小夜子成就自己……。

モンスターユニオンに捕らえられてしまった小夜子を探していたボッカ。その途中偶然に、ココら「チェンタウロ」のメンバーと再会する。そしてボッカはココと二人だけで、敵の「水門塔」に進入する事になるのだが・・・